Sentences with phrase «optical density units»

Not exact matches

The definition of optical depth TAU is the integral from z1 to z2 of k * rho * dz where k is an absorption co-efficient with dimensions of area per unit mass, and rho is the density of the absorber.

Re 423 Chris G — whether the effect saturates at a given density depends on the way the temperature is distributed; if the temperature from TOA downward is isothermal for a sufficient thickness, than the effect could be saturated at TOA (if starting from a large enough optical thickness per unit atmospheric mass path, a change in the density of the gas / etc that contributes optical thickness would then have little to no effect on the flux at TOA, which is what is meant by saturation.